Ceramic heaters have hitherto been used for various applications, as typified by an ignition heater of an oil fan heater and a glow plug for use in assistance to the starting of diesel engine operation. For example, such a ceramic heater is constructed by embedding a heat generating element made of electrically conductive ceramics in a base body made of insulating ceramics. As the material of construction of the heat generating element in such a ceramic heater, there is known a substance composed predominantly of at least one of a silicide of molybdenum or tungsten, a nitride of the same, and a carbide of the same. Moreover, as the material of construction of the base body, there is known a substance composed predominantly of silicon nitride.
However, since the material of construction of the heat generating element is commonly greater in thermal expansion coefficient than the material of construction of the base body, there is the possibility that a crack will appear in the base body due to a thermal stress generated between these materials at the time of heat liberation. With this in view, the addition of a rare-earth component, a silicide of chromium, and an aluminum component to the material for the base body has been proposed as a technique to minimize the difference in thermal expansion coefficient between those materials (refer to Patent Literature 1, for example).